US midterms on course to be the most expensive ever, with spending projected near $12bn

The US midterms campaign is set to be the most expensive on record, with the total cost projected to reach nearly $12bn (£9bn), according to Open Secrets, an independent organisation that tracks campaign finance.

Most of the spending is driven by outside political groups known as Super Political Action Committees (Super Pacs), pouring large sums into some key races ahead of election day on 3 November.

The top individual donor is billionaire businessman Elon Musk, who has spent almost half a billion dollars backing Republican candidates, particularly in Texas, where many of his companies are based.

There are rules on how much people, parties and political action committees (Pacs) can give directly to candidates. But Super Pacs can accept unlimited contributions from individuals, corporations, labour unions and other political committees; they cannot give money directly to candidates but can spend it supporting them indirectly.

According to the latest Federal Election Commission (FEC) filings, which run to mid-October, more than $9.5bn had been spent in this midterms cycle. Pacs and Super Pacs make up more than half of that, at about $5.5bn, with their spending in the last couple of months almost doubling.

Open Secrets has projected the total will reach $11.9bn based on trends in past cycles — about 30% more than what was spent during the last midterm elections in 2022.

The top 40 donors gave $2.4bn up until 14 October, according to the Brennan Center for Justice — a record high for that point in a midterms cycle. 'Spending in the 2026 midterms is shattering records, with more of the money coming from the wealthiest donors and groups this election,' said Michael Beckel, a US campaign finance expert.

Organisations founded by billionaire financier George Soros — Geosor Corp and Fund for Policy Reform — have given a combined $102m to liberal groups. Former New York City mayor Michael Bloomberg has been the biggest Democratic donor, giving more than $60m. Billionaires including Jeff Yass and Richard and Elizabeth Uihlein have each given over $100m to Republican causes.

Musk has given most of his money to America PAC, a Super Pac he set up in 2024, and to the Republican-aligned Senate Leadership Fund. America PAC's investments in the Texas Senate race — supporting Republican Ken Paxton against Democrat James Talarico — total more than $45m, and it has invested around $10m into each of the Senate races in Michigan and Ohio.

'Crypto companies have also been very active this cycle, with Ripple and Coinbase combining to give $63 million to fund Super Pacs promoting the crypto industry's interests,' said Brendan J Glavin of Open Secrets.

Campaigns spend money on staff, voter outreach, rallies and internal polling, but the majority of funds go on advertising, especially television. Ad tracking firm AdImpact recorded $11.15bn spent on advertising up to the end of October, with traditional broadcast television the top beneficiary, though digital ad spending continues to increase. Most advertising money went to the Senate races in Michigan, Texas and Ohio, followed by Iowa and Maine.